one.().relative_identifier(
  two.(),
  key: three.()
).()
one.().relative_identifier(
  two.(),
  key: three.()
)(
  four.(),
  key: five.()
)
one.().relative_identifier key: two.()
one.().relative_identifier unqualified two.(),
                                       key: three.()
one.().relative_identifier two.(),
                           key: three.()